Feb 4, 2011 2:55 PM

I am a Biology student and one of our teachers told us a while ago that the condor is not actually a vulture but rather a stork of some kind, although it does not resemble one. It looks like a vulture because of convergent evolution but has a couple of traits that it shares with storks. From what I remember, one of them is the fact that it keeps its legs warm by splashing (however inappropriate a word) excrements on them. Sadly, I can't remember anything else. What I've read on Wikipedia is everything but clear. They say it is a vulture but place it in the Ciconiiformes order, Cathartidae family. If you click vultures, they are also placed in the Cathartidae family but the order is different-Accipitriformes. Then if you click the Black American Vulture, it says that the order is disputed. Searching Zipcodezoo, I found out that both vultures and condors are placed in Ciconiiformes. While taxonomy is among my interests, I actually wish to know more about the condor-stork business.

The Cathartidae (the family that the California and Andean Condors belong to) has been moved from the order Falconiformes (birds of prey) to the order Ciconiiformes (storks and allies) based mainly on molecular evidence. This has been recently disputed (see here an article proposing to move back condors to the Falconiformes).

For the moment, condors and other vultures are still classified as Ciconiiformes (see Zipcodezoo entry for the Andean Condor).

It has to be made clear that most "other vultures" (i.e. the 16 or so species of "true" vultures of the Old World - Aegypiinae (+ Gypaetinae)) still belongs to (Falconiformes)/Accipitriformes. Only the Cathartidae, the New World "vultures" (seven species, including the two condors), have been moved to Ciconiformes.

On Aegypius monachus it says "This bird is an Old World vulture, and is only distantly related to the New World vultures, which are in a separate family, Cathartidae, of the order Ciconiiformes. It is therefore not directly related to the American Black Vulture despite the similar name and coloration.". The phrase "of the order Ciconiiformes" is somewhat ambigous: it does say that Cathartidae belongs to C, but does it also say that the OW vultures belong there? I think not.

On Accipitridae it says: "The Accipitridae is one of the two major within the order Accipitriformes (the diurnal birds of prey). Many well-known birds, such as hawks, eagles, kites, harriers and Old World vultures are included in this group."

On Cathartidae it says: "Although New World vultures have many resemblances to Old World vultures (traditionally considered part of the bird-of-prey order Falconiformes, though now often classified in a different order), they are not very closely related. Rather, they resemble Old World vultures because of convergent evolution."

The taxonomy sections on Zipcode Zoo seems rather messed up, unfortunately, and don't agree what is actually said in the texts. Even a bird like Falco peregrinus is placed in the Ciconiiformes - which obviously also contains albatrosses and alcids according to what it says next to Ciconiiformes in the taxonomy-section (Diomedea exulans, an arbitrary albatross, is however placed in Procellariformes if one checks its entry). And under Ciconiiformes it says: "Traditionally, the Ciconiiformes has included a variety of large, long-legged wading birds with large bills: storks, herons, egrets, ibises, spoonbills, and several others. Ciconiiformes are known from the Late Eocene. At present the only family retained in the order is the storks, Ciconiidae." and then it says a lot of things that disagree with what was just said. Obviously some parts of Zipcode Zoo follow Sibley & Ahlquist (who stuffed almost anything into the Ciconiiformes - on which almost nobody else agreed), while other don't. The latter ones are much more "mainstream"...(compare to what Zipcode Zoo says under Carthartidae, Falconidae... about the S&A classification: influential, but obviously paraphyletic)

The jury is however still out on where to place the Cathartidae: in Ciconiiformes, Acciptriformes(/Falconiformes) [as done on the AOU's North American checklist] or in their own Cathartiformes [as done by the South American Classifications Committee] - or somewhere else... But nobody (or at least almost nobody - except Zipcode Zoo p.p.) today considers to lump the Old World vultures in the same order as storks.

My guess is that "long ago" someone on ZZ just adopted all of the Sibley & Ahlquist taxonomy for birds (directly or indirectly) for the taxonomical structure (while the texts were written later by real humans and better reflect todays "consensus", or lack thereof). The taxonomical tree itself has not been revised or only partially so (albatrosses are not storks on ZZ, but they possibly once were) - I guess that if you for instance place a genus in for instance Accipitridae, then it automatically gets linked to Ciconiiformes, as Accipitridae is linked there. Well, just my 5p...

Thanks for your detailed answer, Episcophagus. You are right, the site is quite messy, and so is all this taxonomy business.

The birds of prey have been classified as Ciconiiformes based of molecular evidence. The idea was Falcons and Vultures etc. are more closely related to Storks and Gulls etc. than to any other orders of birds. Basically, taxonomists tried to rearrange bird species in strictly monophyletic orders. This means that Ciconiiformes will contain all species descendant from a common ancestor, regardless of their marked differences due to adaptive divergence. It's funny, because at higher taxonomic levels the same rule doesn't apply. Birds are a clade (a branch if you will) in the tree of reptiles. Class Reptilia should include birds if it was to be monophyletic, but instead we have the class Aves (birds) on its own. Why this inconsistency? Systematic categories higher than species (genus, order, class...) are conventional. Their limits are somewhat arbitrary, and the criteria are not agreed upon. Personally, I don't mind the birds of prey being classified as Ciconiiformes, but I wouldn't say that the Condor "is just a stork", just as I wouldn't say Man "is just an ape".

When it comes to traditional taxonomy (with Class, Order, Family... - and all those subs and infras...) it is a "spatially" (i.e. how far is the distance [in breadth, difference - or whatever you will call it] between the taxons) system, while cladistics is only concerned about time. We have to create a principle (not a theory) of relativity in taxonomy - that copes with spacetime... Now we have two systems that don't correspond. IMHO.

To clarify a bit. The traditional taxonomy system changes with time. What once was a species, later gives rise to a genus that perhaps will give rise to a family... it is a cross section of what we have now (yes now, as we didn't have this problem in the Cretaceous or whenever - because we weren't here/there!). Cladistics doesn't do this - it only creates new subdivisions followed by new subdivisions.... as time passes.

Well? Is all life equally old? I think most of us believe so. Not if we count in generatons though, then many bacteria are REALLY old.

Perhaps? A fair system could work something like: Were we separated X genreations ago, then we are different taxons at this or that level (devised by X divided by a chosen number or function - all hypothetically of course!).

(Excuse my mispelligs due to this useless keyboard with stucked keys due to soda-drinking kids or beer-drinking adults!)

Just to clarify a little bit: cladistics isn't concerned about time. In fact, cladograms (the final products of cladistic analysis) don't make any claims about how and when taxa evolved; they are just hypotheses of relationships based on common ancestry. And these are made from an analysis of their shared derived characters (synapomorphies), both morphological and molecular. Cladogram branches are all equal.

If you include time in the equation, you get phylograms that have branches of different lengths according to the time between the inferred splitting events, or between them and the present. That’s phylogeny.

Today I looked up Sibley and Monroe's “A World Checklist of Birds” and saw I missed an important point to make related to Alex’s question. Although all birds of prey are classified as Ciconiiformes today, the Old World vultures are in the family Accipitridae, along with eagles, falcons, hawks, etc. while New World vultures are placed in the family Ciconiidae. This small family contains only seven species of New World vultures, such as the Andean and the Californian Condors (subfamily Cathartinae), and 19 species of true storks, the White Stork and the Jabiru for example (subfamily Ciconiinae).

So, being more closely related to true storks, condors can be seen as modified storks, a result of relatively recent convergent evolution and adaptation to a way of life similar to their distant relatives in the Old World.

This was possible because of their common Ciconiid ancestor. Or, if you prefer, they were “built” at different times on a “stork platform”. Like Seat and Skoda, built on a Volkswagen platform. :-)